1. Field of the Invention
The present invention is useful in the asymmetric syntheses of the various compounds originated from natural products. In more detail, the present invention relates to the mono esters of dicarboxylic acids which are useful in preparing optically active prostaglandins or the like and process for the production thereof.
2. Prior Art
The Diels-Alder reaction (EP-A-0312906), enzymatic hydroylsis of diester moiety or the like is well known as methods for production of optically active half-esters. However, even by such methods, it has been so difficult to prepare a stereochemically pure compound economically on a large scale due to stereochemical impurities, or complicated reactions.
It is significantly useful for the production of various medicinal compounds as well as organic ones from natural sources, if key intermediates are obtained in a high optical purity.
The present invention is designed for syntheses of compounds in much higher optical purity. It is achieved by a stereoselective reaction and by a very easy removal of a small amount of by-products produced in the reaction.
Moreover, the present invention has also an intention of achieving the above-mentioned reaction easily with the inexpensive reagents.